Katherine Hawley

(1971 - 2021)

I argue that, despite van Inwagen’s pessimism about the task, it is worth looking for answers to his General Composition Question. Such answers or ‘principles of composition’ tell us about the relationship between an object and its parts. I compare principles of composition with criteria of identity, arguing that, just as different sorts of thing satisfy different criteria of identity, they may satisfy different principles of composition. Variety in criteria of identity is not taken to reflect ontological variety in the identity relation; I discuss whether variety in principles of composition should be taken to reflect ontological variety in the composition relation

Roughly speaking, perdurantism is the view that ordinary objects persist through time by having temporal parts, whilst endurantism is the view that they persist by being wholly present at different times. (Speaking less roughly will be important later.) It is often thought that perdurantists have an advantage over endurantists when dealing with objects which appear to coincide temporarily: lumps, statues, cats, tail-complements, bisected brains, repaired ships, and the like. Some cases – personal fission, for example – seem to involve temporary coincidence between objects of the same kind. Other cases – a cat and its flesh, a statue and its lump – seem to involve objects of different kinds.

This chapter explores the connections between David Lewis's perdurance theory and his Humean supervenience, arguing that his influential argument about temporary intrinsics is best seen in this light. It presents domestic dispute within the anti‐endurantist camp and analyzes the following questions: why does Lewis identify ordinary objects with world‐bound parts of transworld objects, but not with time‐bound parts of transtemporal objects? Given that Lewis is a counterpart theorist about modality, why isn't he a stage theorist about persistence? Humean supervenience in isolation does not entail perdurance theory, even for the actual world. Lewis's treatment of temporary intrinsics in On the Plurality of Worlds forms part of a discussion of both persistence and its modal analogue, for which there is no neutral term. Perdurance theory is challenged by the stage theory of persistence, which identifies ordinary objects with brief stages instead of transtemporal sums of those stages.

I claim that, if persisting objects have temporal parts, then there are non-supervenient relations between those temporal parts. These are relations which are not determined by intrinsic properties of the temporal parts. I use the Kripke-Armstrong 'rotating homogeneous disc' argument in order to establish this claim, and in doing so I defend and develop that argument. This involves a discussion of instantaneous velocity, and of the causes and effects of rotation. Finally, I compare alternative responses to the rotating disc argument, and consider the implications of my arguments for the doctrines of Humean Supervenience and unrestricted mereology.

‘Fusion’ is a philosophical term of art, with a variety of uses. First, it is often a synonym for ‘sum’. In this sense, a is a fusion of b, c and d iff b, c and d are parts of a, and every part of a shares a part with b, c or d. So a cat is a fusion of the cells which compose it, and the same cat is a fusion of the molecules which compose it. Relatedly, ‘fusion’ can refer to the occurrence of such composition: philosophers disagree about whether fusion is widespread, about whether it can be a vague matter, and so on.

E.J. Lowe claims that quantum physics provides examples of ontic indeterminacy, of vagueness in the world. Any such claim must confront the Evans-Salmon argument to the effect that the notion of ontic indeterminacy is simply incoherent (Evans 1978, Salmon 1981: 243-46). Lowe argues that a standard version of the Evans-Salmon argument fails quite generally (Lowe 1994). Harold Noonan (1995) has outlined a non-standard version of the argument, but Lowe argues that this non-standard version fails for specifically quantum mechanical reasons (Lowe 1997). He claims that it is perfectly coherent to suppose that his quantum case is an example of ontic indeterminacy. In this paper, I raise some objections to Lowe's claim.

In his Material Beings, Peter van Inwagen distinguishes two questions about parthood. What are the conditions necessary and sufficient for some things jointly to compose a whole? What are the conditions necessary and sufficient for a thing to have proper parts? The first of these, the Special Composition Question (SCQ), has been widely discussed, and David Lewis has argued that an important constraint on any answer to the SCQ is that it should not permit borderline cases of composition. This is a far-reaching claim, since many plausible-seeming accounts of composition do permit borderline cases. Ned Markosian has recently directed our attention to the second, the neglected Inverse Special Composition Question (ISCQ). I will argue that those who accept Lewis’s constraint on answers to the SCQ should accept an analogous constraint on answers to the ISCQ, and I will discuss the effects of such a constraint.